bgp router with multi asn's - neighbor config ?

[Leo Vandewoestijne]

On Fri, 26 Sep 2014, Kai wrote:

> protocol bgp me_1 {6
>   local 10.0.0.1 as 1;
>   router id 10.0.0.1;
>   neighbor 10.0.0.9 as 9;
>   direct;
> }
> 
> protocol bgp me_2 {6
>   local 10.0.0.2 as 2;
>   router id 10.0.0.2;
>   neighbor 10.0.0.9 as 9;
>   direct;
> }
> 
> (In fact there are a lot of peers like this one.)
> This setup doesn't seem to work. It seems as if, with each restart, only
> on of the two connections comes online, not always the same one. The
> second connection is rejected when incoming.
>
I'm familiar with that collision, so not surprised.

> Which is the mistake I made here? Or does the peer have to have two IP
> addresses as well?
>
Yes, that's very likely the case.
I've done this with Cisco, Juniper and Foundry neighbours,
and in all cases I ended up using aliased IP's for the same neighbour.
After trial and (many) error, I concluded that appearently Bird can't otherwise make a distinct.


And when re-reading the thread Ondrej Zajicek said that twice:

here subtle:

> Yes, you can have two BGP sessions between two BGP neighbors if you use
> two pairs of IP addresses

and here more clear/explained:

> Incoming sessions are dispatched based on their source addresses.



-- 

Met vriendelijke groet,
With kind regards,


Leo Vandewoestijne